lesion vs pathology

lesion and pathology both are nouns.

Word	Noun	Adjective	Verb	Adverb
lesion	Yes	No	No	No
pathology	Yes	No	No	No

As nouns, pathology is a hypernym of lesion; that is, pathology is a word with a broader meaning than lesion:

lesion (noun)	pathology (noun)
any localized abnormal structural change in a bodily part	the branch of medical science that studies the causes and nature and effects of diseases
an injury to living tissue (especially an injury involving a cut or break in the skin)	any deviation from a healthy or normal condition